Measure the depth of the unit (one of the side panels, from the front edge back to the groove that the back slides into) and get some shelf supports cut. Or, you can use small metal supports (see fig. 1). If using wood, these need to be painted with a child-safe non-toxic paint (like Japlac, also available from B&Q for about £5) or varnish or shellac. This will need time to dry and, if using Japlac, time for the paint fumes to wear off (anything up to a week!). I used 7 shelf supports for 3 full width shelves and one half-width shelf.

fig. 1

Measure the width of the unit and cut a central baton and prime it as with the shelf supports. This will add stability to the cage as well as acting as a convenient strip to cover the gap between the top and bottom doors.

Cut access points in the shelves. The easiest way is to cut a square or rectangle out of one corner, allowing for head height of a rat approaching from up a ladder.

If using melamine off-cuts for your shelves, make sure all edges are covered in melamine. You can buy iron-on rolls of edging to cover those sides you've sawn or trimmed to make the shelf fit.

Buy a length of mesh to fit the whole of the front of the unit. I painted the mesh, on both sides, using Japlac.

ConstructionStep 1

Lay one side panel of the unit on the floor and measure out the gaps between the shelves. I had three evenly spaced shelves with the top half-shelf being just down enough from the top of the unit to allow for an igloo bed to be placed on the shelf. Try to avoid big drops between one shelf and another.

To ensure your shelves are level use a right-angle and a long ruler (or straight bit of wood). Butt the right-angle up to the edge of the laid down unit, at the pencil mark which you drew when deciding on the space between your shelves. Draw along the top of the right-angle and continue the line using a long ruler.

Once you've drawn your lines across one side of the unit, use 2 1/2" screws to attach your primed (and dry!) batons. Line the top of each baton up with the pencil line. Screw from what will be the inside of the cage out, so if any screws break through, the sharp points are on the outside. These can be filed down.

Step 2

I found the easiest way to line up the batons, on what will be the opposite side of the cage, is to simply lie the other side on the floor, next to and lined up (top and bottom) with the side you've already attached the shelf supports to. Using the long ruler, simply continue the line across from the top of each baton to the other side. Once you've drawn the lines, attach the other shelf supports in the same way.

Step 3

Build the unit as instructed in the B&Q instructions.

Step 4

To add strength to the unit you now need to add the central support baton. Measure the gap between the two side shelf supports that will hold the middle (or nearly middle) shelf. Trim your pre-painted/varnished/shellac covered baton to fit, making sure the top edge of it is flush with the top edge of each shelf support. Drill 4 pilot holes through, 2 from each side, and use long screws to secure the central support baton.

Step 5

Next comes the doors. Once the unit has been put together, you can measure it more accurately. How you decide to divide the doors is up to you - I had two doors, the top opening normally, the bottom opening downwards to form a ramp to the floor. You will need 2 lengths of primed baton, each the height of the unit (not including legs), and 4 lengths of primed baton, each the width of the unit. Place one long baton against the front of the unit (flush with the top and bottom) and draw a line across it about halfway down, preferably where the support baton is. Mark the other long baton in the same place and cut to this length (simply butt your marked one against the unmarked one - making sure they are both flush at each end and continue the line across). Using a mitre saw, cut each end at 45 degrees - be careful to cut the right way! (see illustration). Then cut each end of the 4 shorter batons at 45 degrees (again, make sure opposite ends go opposite ways). You have now got the frame for the doors!

On a flat surface, lay the pieces of one door out, butting up the joints at the corners. Hammer in 2 'U' staples to join each piece.

Step 6

Now comes the fiddly bit! With your door frames made, you now need to trim your mesh to fit each door panel. Using the wire cutters, trim the mesh so that you have two pieces, each about 1" smaller all round than each door frame. With the door panels on a flat surface, lay the mesh in place and use 'U' staples to attach it to the frame - start in the middle on one side, then do the opposite side, then opposite ends, trying to keep the mesh reasonably flat. Add more 'U' staples as required, still working on alternate and opposite sides.

Step 7

Once the doors are complete, you need to attach them to the unit. I found it was easier to lay the unit on its back and position the doors by laying them on top of the unit (the top then being what will be the front of the cage). I attached the top door with two hinges on one side, and the bottom door with two hinges on it's bottom edge (make sure the bottom edge of the bottom door is flush with what will be the bottom of the unit). If your carpentry is as good as mine (and mine's terrible!), you'll now see the importance of the central support as it forms a convenient barrier to prevent ratties escaping through the gap between the bottom of the top door and the top of the bottom door!

Step 8

To finish the doors, you now just need to add some catches. I found the simple hook and eye sort to be the easiest to fit and the most effective. For the top door simply screw the 'eye' ring into the opposite edge of the door to the hinges. To make sure you don't put the hook part too far back or up or down, close the door and put the hook into the eye ring, using the screw-in ring on the end of the hook to mark the side of the cage. For the bottom door, I put a catch on each side, at the top.

Step 9

Now you're nearly finished! All you need do now is screw the eyelet hooks into the bottom of each shelf, thinking about what you are going to hang from them. It can be a bit fiddly so I found it easier to lay each shelf on the floor, and then lay each bit of cage furniture on the shelf in its approximate position.

Screw the hooks into what will be the underside of each shelf. For those bits of cage accessories that didn't have their own hooks or attachments, I used 3mm garden wire. But you could also use paper clips or bread ties.

Slide the shelves into position before attaching any accessories, just so you've got some idea of how awkward it might be to remove them for cleaning. You can always re-position the eyelet hooks to make this job easier.